Automatic stoker



il 1927. Apr 5 E. LUNDGREN AUTOMAITIC' STOKER Filed July 27. 1922 3 Sheets-Sheet 1 awwewtofc fb W/A/ ZU/VOG/Pf/V Y 1,623,060 Apnl 5 E. LUNDGREN AUTOMATIC STOKER Filed July 27. 1922 3 Sheets-Sheet 2w April 5, 1927.

E. LUND GREN AUTOMATIC 'STOKER Filed July 27, 1922 3 Sheets-Sheet 5 A? law! I Patented Apr. 5, 1927.

I UNITED STATES EDWIN 'LU'NDGREN,

v 1,623,060 PATENT OFFICE.

OF FREDERICK, MARYLAND, ASSIGNOR TO COMBUSTION ENGI- NEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC STOKER. v

Application filed July 27, 1922. Serial No. 577,824.

the invention in their preferred form, the" section being shown as taken on the line 11 of Fig. 2; Fig. 2 is a sectional plan line 2-2 of Fig. 1; and Fig. 3 is a sectional the line 33 of Fig. 1. p

The furnace illustrated in the drawings is of a common underfeed type having an underfeed grate section 2, an overfeed grate section 4-at the rear of the underfeed section, and an ash pit 6 at the rear of the overfeed section. The underfeed section is made up of a plurality of downwardly and view taken on the plan view taken on rearwardly inclined retorts which are spaced apart, and the outer walls of the outer retorts are spaced from the side walls of the furnace, with rows of tuyere blocks 7 spanning the margins of the adjacent walls of the retorts' and the margins of the outerwalls of the outer retorts and the side walls of the furnace. The fuel while in the course of combustion is fed over the rows of tuyere blocks and the overfeed section by means comprising an auxiliary feeding device 8.

The furnace is further. provided with "a wind box 10 for supplying air to said grate sections, which is provided'with a bottom wall 12 and a. front wall 14. Air under pres sure is supplied tothe wind box 10 through main air supply conduits 16 which extend through the bottom wall 12, and each is provided with a damper 17 for controlling the supply of air to the wind box. The front wall of the ash pit 6 is made up of a hollow tuyere structure 18 located directly beneath the lower end of the overfeed grate section 4, and with a hollow tuyere structure 20 located beneath the structure 18. The exposed walls of the hollow structures 18 and 20 are provided with tuyere openin'gs22, and air is supplied to the interior of said structures from the main supply conduits 16. As shown in Fig 2, each of the tuyere structures 18 and 0 is made in sections which are arranged in groups of three. Each group of sections of the tuyere structure 18 is in communication with an air chamber 23 through a conduit 24, and each group of sections of the tuyere structure 20 is in communication with the air chamber 23 through a conduit 26, the air chamber 23 being in communication with the main supply con- .duits 16 through branch conduits 28. The

supplies of air to the tuyere structures 18 and 20 are independently controlled by dampers 30 and 32 mounted in theconduits varied as desired for different areas of the front wall of the ash pit and that this may be accomplished independently of the supply ofair to the wind box, air to the wind-box being also controllable.

The rear wall oftheash pit comprises tuyere blocks 38 of refractory material constituting the upper portion of the rear wall; a metallic tuyere structure 40 located directly beneath the tuyere blocks and having its exposed wall provided with tuyere openings 42; and a plate 44 located directly beneath the tuyere structure 40 constituting the lower portion of said rear wall ofthe ash pit. A space is provided back of the t'uyere blocks 38 through which air is directed to the tuyere openings in the blocks, and air is supplied to the tuyere structure 40 through an air supply conduit 45.

The furnace illustrated in the drawings is also provided with a clinker crushing roll 46 arranged at the bottom of the ash pit and carried by a squared shaft 47 having its ends journaled in hearings on beams 48 arranged adjacent the side walls of thefurnace. The clinker crushing roll is made up of sections that are arranged in groups of three. corresponding to the group arrangement of the sections of the tuyere structures'18 and 20.

The roll shaft 47 is mounted intermediate its the supply ofroll and mounted on beams 51 corresponding to the beams 48'. The clinker crushing roll is rotated in a clockwise direction by means of aratchet wheel 49 mounted on one end of the roll shaft 47 which extends through the side wall of the furnace. The ratchet wheel 49 is engaged by an actuating pawl 50 carried by an oscillating lever 52 which is actuated by suitable means through a link 54. The clinker crushing roll 46 is provided with clinker crushing teeth 56 which cooperate with'clinker crushing teeth 57 on-the plate 44. The clinker crushing roll is mounted close to the lower end of the toothed plate 44 andis spaced a considerable distance back of the lower end of the .lower' tuyere structure 20. A dump grate 58 extends between the forward portion of'the clinker crushing roll and the lower end of the forward wall of the ash pit and its rear-edge is provided with tooth like projections 59 that eXtendbetween the teethof the roll." This' dump grate is made in sections which are arranged in groups which correspond in arrangement cated at the front of the furnace.

to the groups of sectionsof the tuyere structures 18 and 20 and the clinker crushing roll 46. Each group of sections of the .dump grate is mounted on a shaft 60, the several shafts havingtheir ends journaled in bearings on the beams 48 and 5l. Each group of sections of the dump grate is adapted to be independently swung downwardly and returnedto' its normal refuse supporting position by means of an arm 64 having one end secured to itsshaft and its other end connected by a link 66' with a depending arm of a bell crank 68, the other arm of the bell crankbeing provided with segmental gear teeth'70 that are engaged by aworm 72 carried by a shaft 74 which is adapted to be operated by a hand wheel 76 conveniently lo- This sectional construction of the ,dump grate enables difi'erent parts of the contents of the ash pitto be separately discharged.

The exposed wall of the tuyere structure 18 and the upper portion of ithe exposed wall of the tuyere-structure 20 are inclined downwardly and rearwardly substantially in a plane tangent to the forward portion of the periphery of the clinker crushing roll 46, and the lower portion of said wall of the "structure 20 is inclined downwardly and forwardly to the forward portion of the dump grate 58; The lower portion of the rear wall of the ash pit comprising the metallic tuyere structure 40 and theplate 44 are inclined slightly downwardly and forwardly toward the clinker crushing roll. With this construction it will be apparent that the rearwardly or inwardly inclined portions of the front wall of the ash pit and the inclined portion of the rear wall of the ash pit will cooperate to direct clinkers and ashes down upon the clinker crushing roll,

inclined lower portion of the front wall of the ash pit and said plane which is tangent to the periphery of the roll, is filled, thus insuring proper operation of the roll on all of the heavier particles of the refuse. It will also be apparent that this construction and arrangement enables substantially all of the contents of the ash pit to be dumped out, upon the dump grate being swung down.

The arrangement of the metallic tuyere structure 40 reduces the liability of clinkers forming on the rear wall of the ash pit, and yet this structure is located a suflicient dis tancebelow the bed ofburning fuel to be effectively protected from becoming overheated.

The metallic tuyere structure 40, and the clinker crushing plate 44 are each made up of sections which are arranged in groups corresponding to the sectional arrangement of the tuyere structures 18 and 20, clinker crushing roll 46, and dump grate 58. This sectional arrangement enables the'width of the furnace to be easily extended. v

As will be ,evident to those skilled in the art my invention permits of various modifications without departing .from the spirit thereof or the scope of the appended claims.

What I claim is:

1. A furnace having, in combination, an underfeed grate section, an overfeed grate section, at the rear of the underfeed grate section, an ash pit at the rearof'the overfeed grate section, a clinker crushing roll located adjacent the lower end of therear wall of the ash pit, and a dump grate arranged in a substantially horizontal plane and extending between the clinker crushing roll and the forward wall of the ash pit.

2. A furnace having, in combination, an underfeed grate section, an overfeed grate section at the rear of the underfeed section, an ash pit at the rear of the overfeed section,- a toothed clinker crushing roll located adjacent the lower end of the rear wall of the ash pit, means for rotating the roll in a direction to cause the ashesto be discharged betweenthe roll and said rear wall, and a dump grate extending between .the clinker crushing roll and the forward wall of the roll arranged adjacent the lower end of the rear wall of the ash pit, and a dump grate extending between the clinker crushing roll and the lower end of said lower portion of the front wall of the ash pit.

4. A furnace having, in combination, an underfeed grate section, an overfeed grate section at the rear of the under-feed section, an ash pit at the rear of the overfeed section having the upper portion of its front wall inclined downwardly and rearwardly, and the lower portion thereof inclined downwardly and forwardly, a clinker crushing ward portion of its'peripheral surface arranged tangent to substantially the plane of said inclined upper portion of the front wall of the ash pit, and a dump grate extending between the clinker crushing ,roll and the lower end of the front wall of the ash pit.

EDWIN LUNDGREN. 

